Artificial-foot joint



Oct. 28, 1930. w. EICHHORN 1,779,765

' ARTIFICIAL FOOT JOINT Filed March 2s. 1928 2 Sheets-Sheet 1 II a; If I 4 .f/ \i p l 6 i 12 I 174 0' "/0 fiwenfor."

7 said joint or of the intermediate body forming the same, a rotary piece was arranged to Patented Oct. 28, 1930 V UNITED STATES WILHELM monnomr, or FRANKronr-on-mir nnnn,aqnniranx, AssrenoR or onnl HALF 'ro THE FIRM or r. L. FISCHER, 0E FEEIBURG, BREISGAU, "GER AN AnrrrrcrAL-r oforfjaornri T 1 Application filed March as, 1928, Serial No. 2'65,;;94, -wasq s at yzi; 1119a,?

This invention relates to an artificial footjoint, by means of which thefoot can carry out, with regard to the shank, in amanner knownper se, movements around two axes situated in one plane and intersecting one" another in the sense of the s'upination at simultaneous dorsal and plantar flexionQ The movements were heretofore made possible in that in a vertical plane through the center of the joints,vbetween the jointed or connected faces of the shank and of the foot, an intermediate body, pivoted for movement around two axes intersecting in one plane was clamped, the joints of which were formed by the jointed faces engaging one with the other in a saddle-like manner, whereas, in the metatarsus, independently of rotate around the longitudinal axis of the foot, in order to limit the foot movement in the sense of the dorsal-flexion, notwithstand ing the released supination.

This invention is an improvement of this foot-joint as it obviates certain defects of the same.

An embodiment ofthe invention is illustrated, by way of example, in the accompany- 1 ing drawing, in which:

Fig. 1 is a longitudinal section through the foot anda side-elevationof the intermediate body, enabling the lateral movements, the shank being shown in side elevation.

' Fig. 2 is a section displaced t0 the s tion in Fig. 1 through the WllOle device, .r

viewed from the rear.

' Fig. 3 shows the intermediate body in topplan-view.

Betweenthe shank Us d th f t F an I intermediate body is inserted, Thi i t I r mediate body comprises a rotary elementek situated in front of the'central cross-section plane and a rotary element 6 situated behind the centralcross-section plane, said elements seat 0 and it has-bearing faces 0 formed'o'n arcs around the transverse axis y-y of the aegis-O der: that at Same m ma as,

in a manner known per sgmev ments around tl isj' 'trfansverse amiss- The convx-outersurfifaces of therotary elements]: ande'of the a 'nutq; For securing thenatg-against n- Th s {arrangement presents the advantage t "at it as; ofgli'ttle height more easy: a; be

l leg than locking devices (if oth t mb r-ai tight weight; A spiral sting l oate' ima 'av'it "L ()1( )i t;hef00itd dii a y"? -;1n-the lqwer surface at thegsnankU, tlie-enas ersaid spring teing weasel 1nd short holding heads 8;

t I hank is. ait aana g beth'tema I V a t, al and cs5 '*wellgiii plantar;'fiexing ef fedts'F asrso in'ddrsal fiexingfojfthe 'In'an' er i'l-l iisti'atetliin "0 r shahk' U which onsequence e'ftlie ver yfcon- 9'0 v, I sure mposedapen the-shank -a;n'd a gainst fih' ZffOh-fi rotaryelement 'l The 'ntermedia ody Z6, 0, e inure-metail v ""f' n ovraentsomhe I fond e-vein at tZie eXtremeplantar flexion, as

forexample, when walking down hill and also in the transmission of the Weight of'the body of the person, who wears the artificial leg, from the shank to the foot. 1

At the putting down of the heel neither the F screwing. ascrew 1?; is axially S'cre'Wecl?into the balt ;,the' threads o'f said "screw havin prefy era l oly a pitch opposite to that of the ii'uti'g.

ntrcllertby-the *parson wee wears tneattifi- I forces downwardly directed from the shank nor the forces upwardly directed from the outermost portion of the heelcan exert any tipping moment. For this reason the bearing 5 e, m is arranged behind the central cross-section-plane. The bearings 7e, d and e, m are therefore always uniformly submitted to stress. As the hearings in, d and e, m carry H the load together, each bearing may be coni 10 siderably smaller than heretofore so that the weight is reduced 5 The torsion-forces exerted by the shank U V or by the foot F onto the intermediate body are not intercepted as hitherto by flanges but by the joint faces (79, e) formed by the rotation around the longitudinal axis x, the joint- .faces being suificiently large for this purpose .as they must bev dimensioned according to the loadings by the weight of the body. The

functioning of the whole foot during one step c is-a s follows: 7 r i v When the heel of the foot is put down on the ground, the heel-springu is. compressed r and the foot slides with ,the intermediate body is, c, e mounted on it around the convex- -j0int faces of the bolts 6 of the shank. The .foot carries out definite lateral'movements, owing to the more or less slanting putting .down of the heel and owing to the condition of the ground.

I When the walking continues, the shank U .returns into its initial position U and loads thereby very strongly. thefrontrotarybody.

To ensure a softer and more silent contact asia-leather v is arranged between the shank andthe intermediate body, said leather assuming the positionv at he initial position of the shank, as indicated in dash-and-dot ,An artificial ankle-joint comprising apiv- -oted bolt perpendicular to the sole of the foot 1 .member of said ankle joint. enabling lateral movements of thefoot member with regardto the shank member of the joint, anintermedi- Y .ate body traversed by said bolt rotatable about the longitudinallaxis of saidfoot member and having two aligned bearingsthereon, said bolt being pivoted; upon anaxis substantially in a horizontal plane extending through the axes ofsaid bearingsand two coaxial rotary bearing. elements upon said foot Inember in-which said intermediate body. is rotatable, a nut on the lower end of said foot bolt,

. 5 ascrew screwed in'axial'directioninto said bolt to lock said nut the e d of said {screw it 1 having apitch oppositelydj t d. to thatv of saidnut. c r I VJYE n testimony whereOfI isyigdlllatulr'ea l WILHELM EIGHHQRNf i 

